diff options
author | Andy Wingo <wingo@pobox.com> | 2008-10-16 13:24:39 +0200 |
---|---|---|
committer | Andy Wingo <wingo@pobox.com> | 2008-10-16 13:24:39 +0200 |
commit | 1f40459f5cd2389d0a44b6c46d431ed58f450f3a (patch) | |
tree | 0de6be1a41b25c4652c0372f8b25b6920a1cffac | |
parent | 28a2f57bde42030e96b4c2ab574336c6e8c394b5 (diff) | |
download | guile-1f40459f5cd2389d0a44b6c46d431ed58f450f3a.tar.gz |
ensure that lists pushed onto the stack are proper
I saw this problem when running elisp.test -- it tries to apply a
function to an arglist ending in nil, which obviously is not null.
* libguile/vm-engine.h (PUSH_LIST): New helper macro, pushes the elements
of a list onto the stack. Checks to make sure that the list is proper.
* libguile/vm-i-system.c (list-break, mv-call, apply, goto/apply)
(goto/cc): Use LIST_BREAK.
* libguile/vm-engine.c (vm_error_improper_list): New error case.
-rw-r--r-- | libguile/vm-engine.c | 4 | ||||
-rw-r--r-- | libguile/vm-engine.h | 12 | ||||
-rw-r--r-- | libguile/vm-i-system.c | 15 |
3 files changed, 21 insertions, 10 deletions
diff --git a/libguile/vm-engine.c b/libguile/vm-engine.c index a79786015..3956a389d 100644 --- a/libguile/vm-engine.c +++ b/libguile/vm-engine.c @@ -176,6 +176,10 @@ vm_run (SCM vm, SCM program, SCM args) err_args = SCM_EOL; goto vm_error; + vm_error_improper_list: + err_msg = scm_from_locale_string ("VM: Attempt to unroll an improper list: tail is ~A"); + goto vm_error; + vm_error_no_values: err_msg = scm_from_locale_string ("VM: 0-valued return"); err_args = SCM_EOL; diff --git a/libguile/vm-engine.h b/libguile/vm-engine.h index 22a7ef5e4..215f630b1 100644 --- a/libguile/vm-engine.h +++ b/libguile/vm-engine.h @@ -299,6 +299,18 @@ do \ PUSH (l); \ } while (0) +/* The opposite: push all of the elements in L onto the list. */ +#define PUSH_LIST(l) \ +do \ +{ \ + for (; scm_is_pair (l); l = SCM_CDR (l)) \ + PUSH (SCM_CAR (l)); \ + if (SCM_UNLIKELY (!SCM_NULLP (l))) { \ + err_args = scm_list_1 (l); \ + goto vm_error_improper_list; \ + } \ +} while (0) + /* Below is a (slightly broken) experiment to avoid calling `scm_cell' and to allocate cells on the stack. This is a significant improvement for diff --git a/libguile/vm-i-system.c b/libguile/vm-i-system.c index 80eb9249a..fbb94c89a 100644 --- a/libguile/vm-i-system.c +++ b/libguile/vm-i-system.c @@ -214,8 +214,7 @@ VM_DEFINE_INSTRUCTION (list_break, "list-break", 0, 0, 0) { SCM l; POP (l); - for (; !SCM_NULLP (l); l = SCM_CDR (l)) - PUSH (SCM_CAR (l)); + PUSH_LIST (l); NEXT; } @@ -833,8 +832,7 @@ VM_DEFINE_INSTRUCTION (mv_call, "mv-call", 3, -1, 1) POP (values); values = scm_struct_ref (values, SCM_INUM0); len = scm_length (values); - for (; !SCM_NULLP (values); values = SCM_CDR (values)) - PUSH (SCM_CAR (values)); + PUSH_LIST (values); PUSH (len); ip += offset; } @@ -866,8 +864,7 @@ VM_DEFINE_INSTRUCTION (apply, "apply", 1, -1, 1) if (len < 0) goto vm_error_wrong_type_arg; - for (; !SCM_NULLP (ls); ls = SCM_CDR (ls)) - PUSH (SCM_CAR (ls)); + PUSH_LIST (ls); nargs += len - 2; goto vm_call; @@ -886,8 +883,7 @@ VM_DEFINE_INSTRUCTION (goto_apply, "goto/apply", 1, -1, 1) if (len < 0) goto vm_error_wrong_type_arg; - for (; !SCM_NULLP (ls); ls = SCM_CDR (ls)) - PUSH (SCM_CAR (ls)); + PUSH_LIST (ls); nargs += len - 2; goto vm_goto_args; @@ -949,8 +945,7 @@ VM_DEFINE_INSTRUCTION (goto_cc, "goto/cc", 0, 1, 1) SCM values; values = scm_struct_ref (cont, SCM_INUM0); nvalues = scm_ilength (values); - for (; !SCM_NULLP (values); values = SCM_CDR (values)) - PUSH (SCM_CAR (values)); + PUSH_LIST (values); goto vm_return_values; } else |